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  • 1.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Baldvinsson, Jón Rúnar
    Skatturinn (Iceland Revenue and Customs), Reykjavík, Iceland.
    Wang, Yuxia
    Qamcom Research and Technology, Stockholm, Sweden.
    Exploring LRP and Grad-CAM visualization to interpret multi-label-multi-class pathology prediction using chest radiography2022In: 2022 IEEE 35th International Symposium on Computer-Based Medical Systems (CBMS) / [ed] Linlin Shen; KC Santosh; Alejandro Rodríguez González, IEEE conference proceedings , 2022, p. 258-263Conference paper (Refereed)
    Abstract [en]

    The area of interpretable deep neural networks has received increased attention in recent years due to the need for transparency in various fields, including medicine, healthcare, stock market analysis, compliance with legislation, and law. Layer-wise Relevance Propagation (LRP) and Gradient-weighted Class Activation Mapping (Grad-CAM) are two widely used algorithms to interpret deep neural networks. In this work, we investigated the applicability of these two algorithms in the sensitive application area of interpreting chest radiography images. In order to get a more nuanced and balanced outcome, we use a multi-label classification-based dataset and analyze the model prediction by visualizing the outcome of LRP and Grad-CAM on the chest radiography images. The results show that LRP provides more granular heatmaps than Grad-CAM when applied to the CheXpert dataset classification model. We posit that this is due to the inherent construction difference of these algorithms (LRP is layer-wise accumulation, whereas Grad-CAM focuses primarily on the final sections in the model's architecture). Both can be useful for understanding the classification from a micro or macro level to get a superior and interpretable clinical decision support system.

  • 2.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Henriksson, Aron
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hideyuki, Tanushi
    Karolinska Institutet, Sweden.
    Emil, Thiman
    Karolinska Institutet, Sweden; Karolinska University Hospital, Sweden.
    Pontus, Naucler
    Karolinska Institutet, Sweden; Karolinska University Hospital, Sweden.
    Dalianis, Hercules
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Terminology Expansion with Prototype Embeddings: Extracting Symptoms of Urinary Tract Infection from Clinical Text2021In: Proceedings of the 14th International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2021) - Volume 5: HEALTHINF / [ed] Cátia Pesquita; Ana Fred; Hugo Gamboa, Setúbal: SciTePress , 2021, Vol. 5, p. 47-57Conference paper (Refereed)
    Abstract [en]

    Many natural language processing applications rely on the availability of domain-specific terminologies containing synonyms. To that end, semi-automatic methods for extracting additional synonyms of a given concept from corpora are useful, especially in low-resource domains and noisy genres such as clinical text, where nonstandard language use and misspellings are prevalent. In this study, prototype embeddings based on seed words were used to create representations for (i) specific urinary tract infection (UTI) symptoms and (ii) UTI symptoms in general. Four word embedding methods and two phrase detection methods were evaluated using clinical data from Karolinska University Hospital. It is shown that prototype embeddings can effectively capture semantic information related to UTI symptoms. Using prototype embeddings for specific UTI symptoms led to the extraction of more symptom terms compared to using prototype embeddings for UTI symptoms in general. Overall, 142 additional UTI symp tom terms were identified, yielding a more than 100% increment compared to the initial seed set. The mean average precision across all UTI symptoms was 0.51, and as high as 0.86 for one specific UTI symptom. This study provides an effective and cost-effective solution to terminology expansion with small amounts of labeled data.

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  • 3.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Henriksson, Aron
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Karlsson Valik, John
    Karolinska Institutet, Sweden.
    Ward, Logan
    Treat Systems ApS, Denmark.
    Pontus, Naucler
    Karolinska Institutet, Sweden.
    Dalianis, Hercules
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Deep Learning from Heterogeneous Sequences of Sparse Medical Data for Early Prediction of Sepsis2020In: Proceedings of the 13th International Joint Conference on Biomedical Engineering Systems and Technologies, Volume 5: HEALTHINF / [ed] Federico Cabitza, Ana Fred, Hugo Gamboa, Setúbal: SciTePress , 2020, Vol. 5, p. 45-55Conference paper (Refereed)
    Abstract [en]

    Sepsis is a life-threatening complication to infections, and early treatment is key for survival. Symptoms of sepsis are difficult to recognize, but prediction models using data from electronic health records (EHRs) can facilitate early detection and intervention. Recently, deep learning architectures have been proposed for the early prediction of sepsis. However, most efforts rely on high-resolution data from intensive care units (ICUs). Prediction of sepsis in the non-ICU setting, where hospitalization periods vary greatly in length and data is more sparse, is not as well studied. It is also not clear how to learn effectively from longitudinal EHR data, which can be represented as a sequence of time windows. In this article, we evaluate the use of an LSTM network for early prediction of sepsis according to Sepsis-3 criteria in a general hospital population. An empirical investigation using six different time window sizes is conducted. The best model uses a two-hour window and assumes data is missing not at random, clearly outperforming scoring systems commonly used in healthcare today. It is concluded that the size of the time window has a considerable impact on predictive performance when learning from heterogeneous sequences of sparse medical data for early prediction of sepsis.

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    fulltext
  • 4.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hollmén, Jaakko
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Rahmani Chianeh, Rahim
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    COVID-19 detection from thermal image and tabular medical data utilizing multi-modal machine learning2023In: 2023 IEEE 36th International Symposium on Computer-Based Medical Systems (CBMS): 22-24 June 2023 / [ed] João Rafael Almeida; Myra Spiliopoulou; Jose Alberto Benitez Andrades; Giuseppe Placidi; Alejandro Rodríguez González; Rosa Sicilia; Bridget Kane, 2023, p. 646-653Conference paper (Refereed)
    Abstract [en]

    COVID-19 is a viral infectious disease that has created a global pandemic, resulting in millions of deaths and disrupting the world order. Different machine learning and deep learning approaches were considered to detect it utilizing different medical data. Thermal imaging is a promising option for detecting COVID-19 as it is low-cost, non-invasive, and can be maintained remotely. This work explores the COVID-19 detection issue using the thermal image and associated tabular medical data obtained from a publicly available dataset. We incorporate a multi-modal machine learning approach where we investigate the different combinations of medical and data type modalities to get an improved result. We use different machine learning and deep learning methods, namely random forests, Extreme Gradient Boosting (XGBoost), Multilayer Perceptron (MLP), and Convolutional Neural Network (CNN). Overall multi-modal results outperform any single modalities, and it is observed that the thermal image is a crucial factor in achieving it. XGBoost provided the best result with the area under the receiver operating characteristic curve (AUROC) score of 0.91 and the area under the precision-recall curve (AUPRC) score of 0.81. We also report the average of leave-one-positive-instance-out cross- validation evaluation scores. This average score is consistent with the test evaluation score for random forests and XGBoost methods. Our results suggest that utilizing thermal image with associated tabular medical data could be a viable option to detect COVID-19, and it should be explored further to create and test a real-time, secure, private, and remote COVID-19 detection application in the future.

  • 5.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Rahmani Chianeh, Rahim
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    FedSepsis: A Federated Multi-Modal Deep Learning-Based Internet of Medical Things Application for Early Detection of Sepsis from Electronic Health Records Using Raspberry Pi and Jetson Nano Devices2023In: Sensors, E-ISSN 1424-8220, Vol. 23, no 2, article id 970Article in journal (Refereed)
    Abstract [en]

    The concept of the Internet of Medical Things brings a promising option to utilize various electronic health records stored in different medical devices and servers to create practical but secure clinical decision support systems. To achieve such a system, we need to focus on several aspects, most notably the usability aspect of deploying it using low-end devices. This study introduces one such application, namely FedSepsis, for the early detection of sepsis using electronic health records. We incorporate several cutting-edge deep learning techniques for the prediction and natural-language processing tasks. We also explore the multimodality aspect for the better use of electronic health records. A secure distributed machine learning mechanism is essential to building such a practical internet of medical things application. To address this, we analyze two federated learning techniques. Moreover, we use two different kinds of low-computational edge devices, namely Raspberry Pi and Jetson Nano, to address the challenges of using such a system in a practical setting and report the comparisons. We report several critical system-level information about the devices, namely CPU utilization, disk utilization, process CPU threads in use, process memory in use (non-swap), process memory available (non-swap), system memory utilization, temperature, and network traffic. We publish the prediction results with the evaluation metrics area under the receiver operating characteristic curve, the area under the precision–recall curve, and the earliness to predict sepsis in hours. Our results show that the performance is satisfactory, and with a moderate amount of devices, the federated learning setting results are similar to the single server-centric setting. Multimodality provides the best results compared to any single modality in the input features obtained from the electronic health records. Generative adversarial neural networks provide a clear superiority in handling the sparsity of electronic health records. Multimodality with the generative adversarial neural networks provides the best result: the area under the precision–recall curve is 96.55%, the area under the receiver operating characteristic curve is 99.35%, and earliness is 4.56 h. FedSepsis suggests that incorporating such a concept together with low-end computational devices could be beneficial for all the medical sector stakeholders and should be explored further.

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    FedSepsis: A Federated Multi-Modal Deep Learning-Based Internet of Medical Things Application for Early Detection of Sepsis from Electronic Health Records Using Raspberry Pi and Jetson Nano Devices
  • 6.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Rahmani, Rahim
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Cognitive Internet of Medical Things Architecture for Decision Support Tool to Detect Early Sepsis Using Deep Learning2021In: Biomedical Engineering Systems and Technologies: BIOSTEC 2020 / [ed] Xuesong Ye, Filipe Soares, Elisabetta De Maria, Pedro Gómez Vilda, Federico Cabitza, Ana Fred, Hugo Gamboa, Cham: Springer, 2021, Vol. 1400, p. 366-384Chapter in book (Refereed)
    Abstract [en]

    The internet of medical things (IoMT) is a relatively new territory for the internet of things (IoT) platforms where we can obtain a significant amount of potential benefits with the combination of cognitive computing. Effective utilization of the healthcare data is the critical factor in achieving such potential, which can be a significant challenge as the medical data is extraordinarily heterogeneous and spread across different devices with different degrees of importance and authority. To address this issue, in this paper, we introduce a cognitive internet of medical things architecture with a use case of early sepsis detection using electronic health records. We discuss the various aspects of IoMT architecture. Based on the discussion, we posit that the proposed architecture could improve the overall performance and usability in the IoMT platforms in particular for different IoMT based services and applications. The use of an RNN-LSTM network for early prediction of sepsis according to Sepsis-3 criteria is evaluated with the empirical investigation using six different time window sizes. The best result is obtained from a model using a four-hour window with the assumption that data is missing-not-at-random. It is observed that when learning from heterogeneous sequences of sparse medical data for early prediction of sepsis, the size of the time window has a considerable impact on predictive performance.

  • 7.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Rahmani, Rahim
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Federated Semi-Supervised Multi-Task Learning to Detect COVID-19 and Lungs Segmentation Marking Using Chest Radiography Images and Raspberry Pi Devices: An Internet of Medical Things Application2021In: Sensors, E-ISSN 1424-8220, Vol. 21, no 15, article id 5025Article in journal (Refereed)
    Abstract [en]

    Internet of Medical Things (IoMT) provides an excellent opportunity to investigate better automatic medical decision support tools with the effective integration of various medical equipment and associated data. This study explores two such medical decision-making tasks, namely COVID-19 detection and lung area segmentation detection, using chest radiography images. We also explore different cutting-edge machine learning techniques, such as federated learning, semi-supervised learning, transfer learning, and multi-task learning to explore the issue. To analyze the applicability of computationally less capable edge devices in the IoMT system, we report the results using Raspberry Pi devices as accuracy, precision, recall, Fscore for COVID-19 detection, and average dice score for lung segmentation detection tasks. We also publish the results obtained through server-centric simulation for comparison. The results show that Raspberry Pi-centric devices provide better performance in lung segmentation detection, and server-centric experiments provide better results in COVID-19 detection. We also discuss the IoMT application-centric settings, utilizing medical data and decision support systems, and posit that such a system could benefit all the stakeholders in the IoMT domain.

    Download full text (pdf)
    Federated Semi-Supervised Multi-Task Learning to Detect COVID-19 and Lungs Segmentation Marking Using Chest Radiography Images and Raspberry Pi Devices: An Internet of Medical Things Application
  • 8.
    Alam, Mahbub Ul
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Rahmani, Rahim
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Intelligent context-based healthcare metadata aggregator in internet of medical things platform2020In: Procedia Computer Science, E-ISSN 1877-0509, Vol. 175, p. 411-418Article in journal (Refereed)
    Abstract [en]

    The internet of medical things (IoMT) is relatively new territory for the internet of things (IoT) platforms where we can obtain a significant amount of potential benefits in terms of smart future network computing and intelligent health-care systems. Effective utilization of the health-care data is the key factor here in achieving such potential, which can be a significant challenge as the data is extraordinarily heterogeneous and spread across different devices with different degrees of importance and authority to access it. To address this issue, in this paper, we introduce an intelligent context-based metadata aggregator in the decentralized and distributed edge-based IoMT platform with a use case of early sepsis detection using clinical data. We thoroughly discuss the various aspects of the metadata aggregator and the overall IoMT architecture. Based on the discussion, we posit that the proposed architecture could improve the overall performance and usability in the IoMT platforms in particular for different IoMT based services and applications.

    Download full text (pdf)
    fulltext
  • 9.
    Rahmani, Rahim
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Firouzi, Ramin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Alam, Mahbub Ul
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    A Proximal Algorithm for Fork-Choice in Distributed Ledger Technology for Context-Based Clustering on Edge Computing2020In: Engineering Proceedings, ISSN 2673-4591, Vol. 2, no 1, article id 92Article in journal (Refereed)
    Abstract [en]

    The major challenges of operating data-intensive of Distributed Ledger Technology (DLT) are 1) To reach consensus on the main chain is a set of validators cast public votes to decide on which blocks to finalize and 2) scalability on how to increasing the number of chains which will be running in parallel. In this paper, we introduce a new proximal algorithm that scales DLT in a large scale IoT devices network. We discuss how the algorithm benefits the integrating DLT in IoT by using edge computing technology, taking the scalability and heterogeneous capability of IoT devices into consideration. IoT devices are clustered dynamically into groups based on various proximity context information. A cluster head is used to bridge the IoT devices with the DLT network where the smart contract is deployed. In this way, the security of the IoT is improved and the scalability and latency are solved. We elaborate our mechanism and discuss issues that should be considered and implemented when using the proposed algorithm even we show its behaves when varying parameters like latency or when clustering.

  • 10.
    van der Werff, S. D.
    et al.
    Department of Medicine, Division of Infectious Disease, Karolinska Institutet, Stockholm, Sweden.
    Thiman, Emil
    Department of Medicine Solna, Division of Infectious Disease, Karolinska Institutet, Department of Infectious Diseases, Karolinska University Hospital, Stockholm.
    Tanushi, Hideyuki
    Department of Infectious Diseases, Department of Data Processing & Analysis, Karolinska University Hospital, Stockholm, Sweden.
    Karlsson Valik, John
    Henriksson, Aron
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Alam, Mahbub Ul
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Dalianis, Hercules
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ternhag, Anders
    Karolinska Institutet.
    Nauclér, Pontus
    Department of Medicine Solna, Division of Infectious Disease, Karolinska Institutet, Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.
    The accuracy of fully automated algorithms for surveillance of healthcare-associated urinary tract infections in hospitalized patients2021In: Journal of Hospital Infection, ISSN 0195-6701, E-ISSN 1532-2939, Vol. 110, p. 139-147Article in journal (Refereed)
    Abstract [en]

    Background: Surveillance for healthcare-associated infections such as healthcareassociated urinary tract infections (HA-UTI) is important for directing resources and evaluating interventions. However, traditional surveillance methods are resourceintensive and subject to bias.

    Aim: To develop and validate a fully automated surveillance algorithm for HA-UTI using electronic health record (EHR) data.

    Methods: Five algorithms were developed using EHR data from 2979 admissions at Karolinska University Hospital from 2010 to 2011: (1) positive urine culture (UCx); (2) positive UCx + UTI codes (International Statistical Classification of Diseases and Related Health Problems, 10th revision); (3) positive UCx + UTI-specific antibiotics; (4) positive UCx + fever and/or UTI symptoms; (5) algorithm 4 with negation for fever without UTI symptoms. Natural language processing (NLP) was used for processing free-text medical notes. The algorithms were validated in 1258 potential UTI episodes from January to March 2012 and results extrapolated to all UTI episodes within this period (N 1/4 16,712). The reference standard for HA-UTIs was manual record review according to the European Centre for Disease Prevention and Control (and US Centers for Disease Control and Prevention) definitions by trained healthcare personnel.

    Findings: Of the 1258 UTI episodes, 163 fulfilled the ECDC HA-UTI definition and the algorithms classified 391, 150, 189, 194, and 153 UTI episodes, respectively, as HA-UTI. Algorithms 1, 2, and 3 had insufficient performances. Algorithm 4 achieved better performance and algorithm 5 performed best for surveillance purposes with sensitivity 0.667 (95% confidence interval: 0.594-0.733), specificity 0.997 (0.996-0.998), positive predictive value 0.719 (0.624-0.807) and negative predictive value 0.997 (0.996-0.997).

    Conclusion: A fully automated surveillance algorithm based on NLP to find UTI symptoms in free-text had acceptable performance to detect HA-UTI compared to manual record review. Algorithms based on administrative and microbiology data only were not sufficient.

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